Fix reply in topic after creation.

Telegram/SourceFiles/history/view/controls/history_view_compose_controls.cpp

@@ -112,6 +112,7 @@ public:
 		std::shared_ptr<ChatHelpers::Show> show);
 
 	void setHistory(const SetHistoryArgs &args);
+	void updateTopicRootId(MsgId topicRootId);
 	void init();
 
 	void editMessage(FullMsgId id, bool photoEditAllowed = false);
@@ -229,6 +230,10 @@ void FieldHeader::setHistory(const SetHistoryArgs &args) {
 	_topicRootId = args.topicRootId;
 }
 
+void FieldHeader::updateTopicRootId(MsgId topicRootId) {
+	_topicRootId = topicRootId;
+}
+
 void FieldHeader::init() {
 	sizeValue(
 	) | rpl::start_with_next([=](QSize size) {
@@ -855,6 +860,11 @@ Main::Session &ComposeControls::session() const {
 	return _show->session();
 }
 
+void ComposeControls::updateTopicRootId(MsgId topicRootId) {
+	_topicRootId = topicRootId;
+	_header->updateTopicRootId(_topicRootId);
+}
+
 void ComposeControls::setHistory(SetHistoryArgs &&args) {
 	_showSlowmodeError = std::move(args.showSlowmodeError);
 	_sendActionFactory = std::move(args.sendActionFactory);

Telegram/SourceFiles/history/view/controls/history_view_compose_controls.h

@@ -135,6 +135,7 @@ public:
 
 	[[nodiscard]] Main::Session &session() const;
 	void setHistory(SetHistoryArgs &&args);
+	void updateTopicRootId(MsgId topicRootId);
 	void setCurrentDialogsEntryState(Dialogs::EntryState state);
 	[[nodiscard]] PeerData *sendAsPeer() const;
 

Telegram/SourceFiles/history/view/history_view_replies_section.cpp

@@ -493,6 +493,7 @@ void RepliesWidget::setupTopicViewer() {
 	) | rpl::start_with_next([=](const Data::Session::IdChange &change) {
 		if (_rootId == change.oldId) {
 			_rootId = change.newId.msg;
+			_composeControls->updateTopicRootId(_rootId);
 			_sendAction = owner->sendActionManager().repliesPainter(
 				_history,
 				_rootId);